1. Field of the Invention
The present invention relates to septic systems; e.g., wastewater treatment systems and, more particularly, to an apparatus for use in septic systems connected to a drip irrigation system.
2. Description of Prior Art
Typically the treated water from a septic system; e.g., an aerobic wastewater treatment system (AWWS), is pumped from a pump or holding tank and into a drain field or drip irrigation system through a series of lines which are buried in the drain field, each of the lines having a series of drip emitters or small orifices which discharge small amounts of water from the lines into the drain field. These drip emitters/orifices are readily subject to plugging from solids carried over from the pump tank. To avoid this problem, it is common to use some type of filter system between the pump discharge and the manifold or header to the drip irrigation system. One such system is disclosed in U.S. Pat. No. 5,670,038 ('038 Patent), incorporated herein by reference for all purposes.
In a system marketed by Clearstream Wastewater Systems, Inc., a centrifugal action screen filter known as SPIN CLEAN® marketed by Agricultural Products, Inc. is employed to catch debris that would otherwise pass into the drip field piping and potentially plug the emitters/orifices.
Other types of filters, e.g., disc filters, sand filters, can also be employed between the pump from the pump tank and the piping in the drip or drain field to prevent the emitters/orifices from being plugged by solids carried over from the pump tank.
In all of the systems described above, it is necessary to flush the drip lines of the drip irrigation systems which is typically accomplished by temporarily pressurizing the lines and returning the water from the drip lines back to the pretreatment/trash tank or aerobic tank in an AWWS for further treatment. Since the flushing is carried out each time the pump is activated, it will be understood that a significant amount of water is being recycled to the AWWS. This return of a large volume of water into the system places an extra load on the system by increasing throughput through the system and requires a larger pump. Furthermore the return of this water back to the trash tank reduces the output of the pump in the pump tank as well as its pressure thereby decreasing the pump efficiency downstream, i.e., in the drip field. Further, in most prior art systems, there is semi-continuous backwashing or flushing of the filters when the pump is running meaning that, there is a further increase in the volume through the AWWS and compromised efficiency of the pump. Although the volume of recycle can be controlled with an electric solenoid valve, such a system involves electric power, timers, sensors, etc.